Serum or Plasma Creatinine Concentration (Substance Concentration)

Why This Test Matters

Creatinine is a byproduct of muscle breakdown and is naturally filtered out by your kidneys. If your kidneys aren’t working properly, creatinine levels can build up in your blood. This test helps doctors monitor kidney health, especially in people with conditions like diabetes, high blood pressure, or those taking certain medications that affect kidney function.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small needle inserted into your arm or a blood sample collected from a finger prick. If your doctor suspects kidney issues, they might ask you to avoid certain medications or fluids for a short time before testing.

What the Results Mean

Higher than expected creatinine levels may indicate reduced kidney function, while lower levels might suggest overhydration or other conditions. Your doctor will compare your results with your baseline and other health factors to interpret them correctly.

Common Causes of Abnormal Results

Elevated creatinine can result from kidney disease, dehydration, severe muscle injury, or conditions that restrict blood flow to the kidneys. Lower levels could be due to overhydration, certain medications, or rare genetic factors.